The present invention relates generally to equipment utilized and operations performed in conjunction with a subterranean well and, in an embodiment described herein, more particularly provides an expandable well screen having a temporary sealing substance.
It is desirable to be able to circulate through a well screen while installing the screen in a well. In the past, such circulation has been provided by a washpipe extending through the screen. The washpipe permits fluid to be circulated through the screen before, during and after the screen is conveyed into the well, without-allowing debris, mud, etc. to clog the screen.
Expandable screens have been used in the past, either with or without the use of a washpipe. When the washpipe is used, a separate trip into the well is typically needed to expand the screen after the washpipe is removed from the screen. When the washpipe is not used, there is no sealed path available in the screen assembly to allow fluids to be pumped from the top of the screen to the bottom. As a result, any attempts to circulate fluid in the well would result in large volumes of fluid being pumped through the screen media, potentially plugging or clogging the screen.
Therefore, it may be seen that improved methods and systems are needed to permit circulation through an expandable well screen during its installation in a well, while not requiring an additional trip into the well to expand the screen. Other benefits could also be provided by improved methods and systems for installing well screens in a well.